Method and apparatus for removing heat fusible material from cans



March 11, 1952 A. F. Rus

' METHOD AND APPARATUS FOR REMOVING HEAT FUSIBLE MATERIAL FROM cANs 4 Sheets-Sheet l Filed NOV. 14, 1947 March 1l, 1952 A. F. RUS 2,589,143

METHOD AND APPARATUS FOR REMOVING HEAT FUSIBLE MATERIAL FROM cANs Filed Nov. 14, 1947 4 sheets-sheet 2 March 11, 1952 A. F. RUS

METHOD AND APPARATUS FOR REMovING HEAT FUSIELE MATERIAL FROM cANs Filed Nov. 14, 1947 4 Sheets-Sheet 5 7 l MR ,w VF. A A

WN ms March l1, 41952 4 Sheets-Sheet 4 Filed NOV. 14, 1947 Patented Mar. 1l, 1952 ME'VIHGD AND 4"APPARATUS *FR REMO-VNG HEAT FUSIBLE MATERIAL FRGM .CANS

Albert Ij. Rus, Chicago, Ill., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation Yof New York Application November 14, 194i, Serial No.1 786,018,

13`Clai'ms. 1 This invention relates to a method ot andv an apparatus for removing heat fusible material from cans.

Iny the manufacture of some condensers it is customary to pot the condenser in a canv usingV wax or some other similar material-to ll'the spaces between the condenser and the interior Walls of the can after the` open end of the ycan is closed with a terminal plate. 1f the can is lled to the top with wax. use of the condenserv ina warm spot would causethe waxl to expand and be extruded from openings in the can. To avoid such occurrences it is necessary that a space be provided in the can to allow for expansion of the Wax without causing messy extrusion of the wax.

It is an object of this invention to provide a method of and an apparatus for removing a portion ofthe sealing compound from .potted-electrical devices. l

In accordance with oneembodiment of this invention an apparatus and method are'provided for partially dewaxing canned condensers wherein the condenser cans are held on rotatablerlxtures mounted on an endless conveyor. chain which at one section travels parallel with a reciprocable carriage having mounted thereon a hot air manifold provided with a plurality of hot air jetsv aimed at the tops of thepassing condensers which are provided with small holes in their top surfaces. As the condensers are carried past the manifold the carriage with the manifold is reciprocated in a line parallel to the moving chain by being intermittently engaged by the chain and released therefrom therebypermittng a greater concentration of the hot air blaston each condenser. While the condensers are being carried past the hot air manifold the fixtures on which they are mounted are engaged Aby a mechanism which causes them to spin around a vertical axis. The hot air blasts rst melt the wax at the upper end of the can and then aspirato a portion of the melted Wax from within thecondenseican which portion is then blown away togetherv with any other wax accumulated on the outside of the can.

A complete understanding of the invention will be had by reference to the following detailed specification taken in conjunction with the accompanying drawings,l in which Fig. 1 is a side elevation partly-insection of an apparatus embodying the features of the invention, the section being taken on the line I-.I of Fig. 2;

Fig. 2 is a plan section with some parts -in ele- 2 vation of the apparatus shown in Fig. 1 taken on theline 2--2 of that figure;

Fig. 3 isa view showing most .of the mechanical vportion of the apparatus in front elevation and taken through a section of the hood on'the line 3--3 of Fig. l2;

Fig. 4 is a partial plan sectional'view 'ofthe apparatus shown in Fig. 'partlyV in elevation and taken along ,the line li-4 of Fig. 3;

Fig. 5 is a vertical sectional view of the' apparatusv shown in Fig. 2' taken along the line"5'5"of that figure;

Fig. 6 is a vertical'sectionof the apparatus shown in Fig. 2 taken along the line 6-6 of that figure;

Fig. '7 is a` plan view of one of the spinning vfixtures which hold individual condensers;

Fig. 8 is a front elevation of the spinning fixtures shown in Fig. 7, the condenserin the fixture being shown in the condition' which prevails after someof the wax has been' aspirated;

Fig. 9 is a sectional view of a spinner taken along .the line 9-9`of Fig. 8; and

Fig. 10'is a vertical sectional view with parts shown in elevation, taken along the `line 10j-ID of Fig. 7.

In one method of the manufacture of condensers of the type indicated at Zin the drawings, the electrical elements 2l (Fig. 8) are potted in wax 22 by placing them and a terminal plate 23 connected thereto'into an'open ended can 24 and crimpingthe open edge of the can around the terminal plate after which the can isthoroughly lled with molten Wax under a substantial vacuum.l The wax enters the can through holes 25j provided in the terminal plate. As a result of this operation the spaces inthe can are filled with wax which extends up to the terminal platein the interior of the can. During'the cooling period, voids dueto contraction of the wax are prevented by `steps whichprovide a continuous'inux of wax into the can duringjthe coolin'gvstep'. If nothing `further is' done such'a condenser when subjectedito abnormally high temperatures' will extrudewax because of a lack of space within the condenser for expansion ofthe wax. The specificembodimentof` theapparatus described herein is ideally suited for providing a space within a canned condenser'to allow room for the expansion of wax by removing a portionoi the wax from the canned condenser after it hasbeen' completely assembled and filled with wax.

Asshown in the drawings the. apparatus is supported .by a rectangular base plate .26 mounted on a frame 21. Secured to the base plate 26 ad'v jacent three corners thereof are three vertically disposed spindles 30, 3| and 32 on which idler sprocket wheels 33, 34 and 35 are mounted for free rotation. The sprocket wheels are maintained in their vertical position by retaining collars 40, 4| and 42 secured to the spindles 30, 3| and 32, respectively. At the fourth corner, the base plate is provided with a sprocket wheel 43 securely fixed to a shaft 44 extending upward from a reduction gear box 45 which is secured toy the base plate 26 and is coupled to a motor 48, which, through the gear box, imparts a relatively slow rotation to the sprocket wheel 43.

A plurality of rotatable article holding fixtures 41 are carried by a continuous conveyor formed by an endless sprocket chain 48 stretched around the sprocket wheels 33, 34, 35 and 43 in the form of a rectangle with the links of the chain engaging the teeth of the four sprocket wheels. It will be seen that rotation of the sprocket wheel 43 in the direction of the arrow 49 (Fig. 2) by the motor 46 will impart horizontal motion -to the endless chain 48 in the direction of the arrows 50 and 5|.

The sprocket chain 48 (Figs. 5 and 6) comprises a series of side links 52 and 53 and flexible joints 54 and 55 formed by concentric tubular cross members 60 and 6|. Each of the joints 54 is provided with .a solid pin 62 which extends through the hollow joint and is upset at each end. Instead of the solid pin 62, a bushing 63 having an annular iiange 64 extends through the hollow portion of the joints 55 and provides a vertical bearing for a rotatable spindle 65 which carries an article carrying fixture 41 securely xed to its upper end by a locking pin 1|. To reduce friction and to maintain the fixtures 41 at a predetermined height a spacing sleeve 12 surrounds the spindle 65 between a projecting annular portion 13 of a circular base member 14 of the xture 41 and the annular iiange 64. Fixed to the lower end of the spindle 65 is a worm gear which is separated from the lower end of the bushing 63 by a washer 60. A floating sleeve 8| engageable with a drag bar hereinafter described surrounds the lower end of the bushing 63 between the lower side of the chain andthe washer 80.

The plate 14 carries gibs 82-82 which are slideably engaged by the walls of grooves 83--83 of two movable segments 84 and 85 thus to support the segments for movement toward and away from each other. Extending across the plate 14 between the two segments 84 and 85 fis a spacer bar 86 which is fixed to the plate' 14 and which has fixed toit a circular plate 00.

The plate 90 has elongated slots 9|9| formed in it through which extend article gripping fingers 92-92 and 93-93 fastened to the segments 84 and 85. .Additional article gripping lingers 94 are securedfto the plate 90 to form with the other angers' enartieie hoiding nest.

The segments 84 and 85 are provided with oppositely threaded coaxial apertures 95 and 96 in which is threaded a screw member 91 having right hand threads at one end and left hand threads at the opposite end. The center portion of the screw member 91 is movably disposed within an aperture 98 in the bar 86 and is restricted from longitudinal movement by a pair of fixed pins 99-99 passing through an annular groove 81 at the center of the screw member 91 and driven through the bar 85. Rotation of the screw member 91 operates to move the pairs of fingers V'92--92 and 93-93 toward and away from each other so that the size of the nest formed by all the fingers may be preset to t the condenser being operated on. A flat spring member |00 secured to the plate 90 is provided with a small key projection |0| which is engageable With the slotted end of the screw member 91 to lock it in an adjusted position after it has been rotated to effect any predetermined adjustment of the ngers 92-92 and 93-93.

Each of the worm gears 15 is engageable with a driving worm |02 extending parallel to that side of the conveyor chain 48 adjacent the front of the apparatus as shown in Figs. 3 and 4. The driving worm |02 is rotatably mounted in a plurality of bearings |03 secured to the base 26 and is driven by a motor |04. Slots |05 are provided in one side of the bearings to expose a portion of the driving worm in order to permit engagement between the driving worm and the worm gears 15 along the entire length of the driving worm. In order to ensure positive engagement between the worm gears 15 and the driving Worm |02, a pair of parallel guides |01 supported by brackets |08 fixed to the base 26 are disposed on each side of the chain 48 along the front portion thereof.

Adjacent to the driving Worm |02 and parallel to the conveyor chain 48 is a reciprocable carriage |06 mounted on flanged wheels ||0 which ride on sets of rails secured to the base 25 and parallel to the driving worm |02. Supporting uprights ||2 and ||3 on the carriage support a hot air manifold ||4 connected at one end through a iiexible pipe ||5 to a source of hot air under pressure, not shown. Clamps |20 and |2| serve to hold the manifold rigid with respect to the supporting uprights ||2 and ||3. A plu rality of iiared-end jets ||6 (Fig. 5) are provided on that side of the manifold ||4 which -is ad-l jacent to the conveyor chain 48. The jets communicate with the interior of the manifold and are disposed at such an angle that they are aimed at articles carried by the xtures 41.

A heavy coil spring |22 secured to the right end of the carriage |06 and to an anchor |23 on the base 24 exerts a continuous pull on the carriage urging it to the right (Figs. 2 and 3). Movement of the carriage |06 to the right (Figs. 2 and 3) is limited by a pair of columns |24 and braking arms |25 supported thereby under the pressure of springs |30. The columns |24 are fixed to the base 26 at the right end of the left set of rails (Figs. 2 and 4) and carry the braking arms in position to resiliently engage the Wheels ||0.

Reciprocation of the carriage |06 is provided by a mechanism comprising a fiat drag bar |3l (Fig. 4) pivotally connected near one end to the base of the carriage |06 and extending outwardly from the carriage to engage the iioating sleeves 8| just above the worm gears 15 as theyy are carried to the left as shown in Figs. 2 and 3, and to the right as shown in Fig. 6, by the chain 48. At the beginning of the reciprocating cycle the lever |3| is locked in the position shown in full lines in Fig. 4 by a pin |32 secured to the base ascia-143 thereby constantly urging the arm |34 of the bell crank lever toward the end of the drag bar |3|. A spring |42 connected to the drag bar |3| and anchored to the base of the carriage |55 constantly urges the lever |3| to the right or clockwise (Fig. 4').

Asthe conveyor chain moves to the left (Fig. 4) the drag bar |3| is engaged by the iioating sleeve 8| nearest the right side of the drag bar |31, and the lever |3| being locked, the carriage |55 will be moved by the chain 48 to the left a distance approximately equal to the space between twov fixtures 41. When this position isreached (Fig. 4,- dot and dash lines) the arm. |40 of the bell crank lever |35 will strike the end of a stop screw |43 threaded into a post |44 secured to the base 25 whereupon the.l end of the arm |40 will be moved to the right against the action of the spring |4| thereby breaking the locking engagement between the projection |33 0f the arm |34 and the drag bar |3I. The spring |22 having more potential force than the spring |42, the carriage |06 will be snapped to the right (Fig. 4) the braking arms |25 acting to cushion the shock, and, after the drag bar |3| pivots and clears the sleeve 8| last engaged by it, the drag bar |31 will be pulled to the right by spring |42. and again locked in its original position by the bell crank. lever |35 in which position it will be engaged by the next succeeding sleeve 8| to repeat the cycle of reciprocation..

Since it is desirable to melt only a small portion` of the wax within the tcp part of the can it is necessary to keep theY rest of the condenser relatively cool. This may be accomplished by covering a substantial portion of the apparatus with an exhaust hood |45 connected to a conduit |5| leading to .an exhaust fan not shown (Fig. l) For easy access to the apparatus under the hood a sloping cover |55 with hinges may be provided for the front part of the hood. The

xtures 41 on the conveyor chain 48 enter the hood through an opening |52 and leave the hood through an opening |53 which opens into a cooling chamber |54 adjacent to and communicating with the. main chamber of the hood. After passing through the cooling chamber |54 the nxtures finallyemerge from an opening |55 at the other end of. the chamber. Operation of the exhaust fan draws the spent hot air from the hood and causes cool air to be sucked through the openings |52 and |55. lThe cool air drawn through the opening. |55 passes through the cooling chamber into the hood through the opening |53 (Fig. l) between the hood and the cooling, chamber.

In the .operation of the apparatus condensers to bev dewaxed may be .loaded onto the moving conveyor at any point of its travel outside of the hood.V After the loaded fixtures 41 are carried into the: hood, the worm gears successively engage the rotating driving worm |02 thereby causing the fixtures 41 to spin on the spindles 65 as they move past the reciprocating manifold. Pressurized hot air from the manifold jets |`|6 is directed onto the upper portion of the'condenser', the angle of the jets being such that the top of the condenser is swept by a current of hot air which after melting the wax at the top of the condenser can, within and without, aspirates a portion of the melted wax from within the can through the holes (Figs. '1 and 8) provided for that purpose. The spacing o1"- the jetsis the same as the spacing between the axes of .rotation of the xtur'es 41 and the manifold is so related to the conveyor chain 48 that each jet-'is directed` at` the centerof theztopof the spinning condensers-during the leftward movement of the. reciprocating cycle (Fig. 3i). The reciprocation of the manifold` |41` causes each hot air jet to intermittently travel with. eachspinning condenser thus. providing agreater concentrationV offhot airv under pressure on tcp of the` spinning condensers. It willbe apparent that each condenser' moving past thev manifold is oonsecutively subjected to a` sustained'b'last of hot airA from each jet..` The aspiration of thel `wax is more uniform andthe space and the top rlevel of the Wax remaining within the condenserl is more symmetrical due. to the` spinning ofv the condensers as they pass the Vmanifold, jets. In addition to aspirating wax fromwithin. the condenser the hotiairblast also melts and blows away anyfother wax accumulated on the upper surface` of the outside of the condenser. The dewaxed condensersxthen pass through the cooling chamber and maybe removed from the fixtures after they emerge from the opening |55.

The embodiment described herein is designed to dewax cans on a. mass production basis. However, itis entirely within the spirit and scope of the present invention to vaspirate a portion of wax or otherheatV fusible compound from a single can provided with, openings therefor byr subjecting that surfaceA of. the can provided with holes to hot air under pressure for a suiiicient length of time to nrst. -melt .a portion of the wax and with a -continuationofthe same current'of hot air to aspirate thev melted Wax through the holes provided therefor in the can. As was pointed out before, the removal of the `wax is more uniform and the space resulting. therefrom is more regular-.and symmetrical'if, while being subjected to the pressurized hot air, the can is spun around an axis. For example, if the motor 46 is stopped and the conveyor chain 48 remains stationary a single condenser can could be dewaxed by placing` it in one of the fixtures 41 disposed next to the manifold |4 and in line with one of the jets H6. The. can may then be subjected to a stream of hot air from the jet stationed nearest thereto for a suiilcient length of time to melt and aspirate a portion of thev wax during which time the fixture holding the condenser may be rotated to spin the can by means of the worm gear 15 and the rotating driving worm |02.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

Whatis claimed is:

1. A method of removing heat fusible compound from a container having an apertured surface therefor comprising directing a stream of hot air on said surface and across the aperture therein to melt a portion of the compound within the can and continuing said stream of hot air on and across said aperture for a suicient length of time to aspirate adesired portion of said melted compound through the aperture in said surface.

2. A method of removing heat fusible compound from a container having an apertured surface thereforcomprising spinning said container around an axis passing through said surfaceat an angle thereto, simultaneously directing a stream of hot air on and across said surface for a sufcient'length of time to melt a portion of the compound within the container and continuing said stream of hot air on and across said surface for a sufficient length of time to aspirate a desired portion of the melted compound from within the container.

3. The method of removing a heat fusible sealing material from a container having an aperture therein which comprises moving the container through a -xed predetermined path, imparting rotation to the container while traveling in said path, applying a blast of hot air onto the container and across the aperture therein during its travel in said path and while being rotated, and flowing a coolant about the container to restrict the heating effect to the portion thereof adjacent the aperture.

4. The method of removing a heat fusible sealing material from a container having an aperture therein which comprises moving a container through a fixed path, imparting rotation to said container during a portion of its movement in said fixed path, continuously applying a jet of hot air tangentially of the aperture in the container during that portion of the travel of the container where it is being rotated and flowing cool air about the container during its travel to restrict the heating eiect of the jet of hot air to a selected portion of the container thereby to liquify and aspirate a predetermined amount of the heat fusible material from the container.

5. A method of removing heat fusible material from a can having an apertured surface comprising heating a portion of the can to melt a portion of the material within the can, spinning said can about an axis extending through said surface at an angle thereto, and directing a current 'of hot air across the apertured surface of the spinning can to aspirate some of the melted material from within the can.

6. A method of removing excess heat fusible sealing material from a container having an aperture in one of its Walls comprising applying a jet of hot air onto said container in the area of said aperture to heat selected portions of said container to fuse a portion of the sealing material, rotating said container, and applying'a coolant to other portions of the container to aid in restricting the heat to said selected portions.

7. An apparatus for removing heat fusible compound from cans comprising a conveyor, means for moving said conveyor, a rotatable can holding fixture carried by said conveyor along a predetermined path, a movable air jet disposed along said predetermined path, said jet being adapted to be connected to a source of hot air under pressure and to direct a stream of hot air on and across a can in said fixture as it is carried past the jet by the conveyor, means for moving said jet while trained on said can in unison with said conveyor for a predetermined distance, and

in said predetermined path, a movable air jet connectible to a source of hot air under :pressure and directed across said predetermined path, means for reciprocating said air'jet in a line pai'- allel to said predetermined path, said jet travelling in unison with said conveyor during one part of the cycle of reciprocation, and means for 8 rotating said fixture during said one part of the cycle of reciprocation.

9. An apparatus for melting and aspirating heat fusible compound from within cans, said apparatus comprising an endless conveyor movable in a predetermined path, means for moving said conveyor, a plurality of rotatable can holding fixtures carried in spaced relation by said con veyor, a hot air manifold having a plurality of spaced apart nozzles connectible to a source of hot air, said nozzles being adapted to direct a stream of hot air across said predetermined path, means associated with said conveyor for reciprocating said manifold within :predetermined limits in a line parallel to said predetermined path, each of said nozzles being directed at and travelling in unison with a separate one of said can holding fixtures during one part of the cycle of said reciprocation, and means for spinning said fixtures as they are carried between said predetermined limits.

10. An apparatus for removing heat fusible compound from within cans having an apertured portion, comprising a plurality of rotatable can holding fixtures carried in spaced relation by a moving conveyor, a movable hot air manifold having a plurality of jets and adapted to be connected to a source of hot air under pressure, means to reciprocate said manifold along a line parallel to the line of travel of said conveyor and in timed relation therewith so that during that part of the reciprocating cycle in which the manifold travels in the same direction as the moving conveyor that part of the manifolds movement will be at the same speed as that of the moving conveyor and each `iet will be trained on and travel with a can being carried by the conveyor, and means for rotating said fixtures during said part of the reciprocating cycle of the manifold.

l1. An apparatus for aspirating liquied heat fusible compounds from cans having an apertured wall comprising a conveyor, a plurality of rotatable can holding fixtures mounted on rotatable spindles carried by said conveyor, a worm gear fixed to each of said spindles, means for moving said conveyor in a predetermined path, a plurality of hot air nozzles connectible to a source of hot air and mounted on a movable support, said nozzles being directed to flow streams of hot air across said predetermined path, means associated with said conveyor for moving said support from a first position to a second position, means for restoring said support to said first position, a driving worm for engaging said worm gears between said first and second position to spin said fixtures, and means for imparting rotation to said driving worm.

l2. A method of removing heat fusible compound from within a closed container having an apertured surface, which comprises spinning said container around an axis extending through said apertured surface at an angle thereto, melting a portion of the compound within the container adjacent the apertured surface, and directing a stream of hot air onto said surface and across said aperture to aspirate a portion of said melted compound.

13. A method of removing heat fusible compound from within a closed container having an apertured surface which comprises positioning the container with the apertured surface uppermost, heating the upper portion of the container to melt the upper portion of the compound within the container, and directing a stream of hot air onto the apertured surface of the container and across the aperture therein to asprate a, portion lof the melted compound.

ALBERT F. RUS.

REFERENCES CITED The following references are of record in the le of this patent:

Jonas Dec. 23, 1947 

